Alpha & Omega Semiconductor Inc. AOL1428

Overview

AOL1428 from Alpha & Omega Semiconductor is an N-channel enhancement-mode MOSFET in Ultra SO-8 package, rated for 30 V drain-source voltage, 45 A continuous drain current at TC=100°C, and 9.5 mΩ R_DS(ON) at V_GS = 10 V. It serves as a high-side switch in DC-DC converters and synchronous rectifiers.

For engineers reviewing the AOL1428 datasheet, pinout, applications, or equivalent options, key selection criteria include its trench-based low-R_DS(ON) performance, UIS-tested ruggedness, gate charge of 18 nC (10 V), body diode recovery time of 29 ns, and thermal resistance R_θJC = 3.5 °C/W - all critical for high-efficiency SMPS design.

Technical Context

The AOL1428 employs advanced trench-gate technology to achieve low conduction loss and fast switching. Its 9.5 mΩ R_DS(ON) at V_GS = 10 V and 16 mΩ at V_GS = 4.5 V enable efficient operation in 5 V–12 V gate-drive systems. The device supports unclamped inductive switching with 135 mJ avalanche energy rating.

Thermal design is enabled by a bottom-tab drain-connected package (R_θJC = 3.5 °C/W) and validated SOA curves up to 100 µs pulses. Dynamic parameters include Q_g = 18 nC, Q_gd = 4.8 nC, and t_r/t_f < 6 ns, supporting MHz-range switching in synchronous buck topologies.

Key Specifications

Pinout & Package

Ultra SO-8 package with exposed drain pad on bottom side; drain internally connected to the thermal tab for enhanced heat transfer. Standard SO-8 footprint with G-S-D-D-S-G pin sequence (top view).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel MOSFET applications.

Compared with BSC014N04LS and SiR872DP, the AOL1428 offers balanced trade-offs: lower Q_g than BSC014N04LS for easier drive, superior E_AR vs. SiR872DP for reliability in inductive loads, and identical SO-8 thermal interface for drop-in layout reuse.

Availability

AOL1428 is available at Aetrix Electronics and suitable for server VRMs, USB-C PD adapters, industrial motor drives, and automotive infotainment DC-DC converters requiring stable component supply and long-term manufacturability.

Supply support for AOL1428 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Alpha & Omega Semiconductor (AOS) is a fabless power semiconductor company specializing in high-performance MOSFETs, IGBTs, and power ICs for computing, consumer, and industrial markets.

The AOL1428 belongs to AOS's Ultra SO-8 trench-MOSFET product line, engineered for high-efficiency, high-current DC-DC conversion where low R_DS(ON), fast switching, and rugged avalanche performance are essential.

FAQ

What is the maximum continuous drain current rating for AOL1428 at 100°C case temperature?

The AOL1428 supports 45 A continuous drain current at T_C = 100°C, as specified in the Absolute Maximum Ratings table. This rating assumes proper PCB thermal design with ≥2 oz copper and thermal vias under the drain tab. At T_C = 25°C, the rating increases to 120 A, but practical operation is limited by junction temperature (T_J ≤ 175°C) and system-level cooling capacity.

Does AOL1428 support 5 V gate drive in logic-level applications?

Yes, the AOL1428 is fully characterized for 4.5 V gate drive, delivering R_DS(ON) < 16 mΩ under that condition. Its gate threshold voltage (V_GS(th)) ranges from 1.0 V to 2.5 V, ensuring reliable turn-on with standard 5 V microcontroller outputs or gate drivers. The 8.5 nC Q_g at 4.5 V further confirms suitability for low-voltage drive systems.

Is AOL1428 qualified for automotive applications?

No, the AOL1428 is explicitly designed and qualified for the consumer market only. The datasheet states: "THIS PRODUCT HAS BEEN DESIGNED AND QUALIFIED FOR THE CONSUMER MARKET. APPLICATIONS OR USES AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS ARE NOT AUTHORIZED." It does not meet AEC-Q101 stress test requirements or automotive PPAP documentation standards.

What is the thermal resistance from junction to case (RθJC) for AOL1428, and how is it measured?

The AOL1428 has R_θJC = 3.5 °C/W, measured with the device mounted to a large heatsink under controlled lab conditions (Note F). This value reflects the intrinsic thermal path from silicon die to the exposed drain tab. In real PCB layouts, effective R_θJC depends on solder coverage, thermal via count, and copper area - typical production values range from 4.0 to 5.5 °C/W.

Can AOL1428 be used in synchronous rectification topologies?

Yes, the AOL1428 is well-suited for synchronous rectification due to its fast body diode characteristics: t_rr = 29 ns and Q_rr = 24 nC at I_F = 20 A. These parameters minimize reverse recovery loss and enable tight dead-time control. Its low R_DS(ON) also reduces conduction loss compared to Schottky diodes in 3.3–12 V output stages.